The present invention relates to an information transmission system using a keyboard of a pushphone and, more particularly, to a system for transmitting alphanumeric sentences entered by the keyboard of the pushphone.
A conventional pushphone has a keyboard consisting of 12 keys. The 12 keys consist of 10 numeric keys 1 to 0 and two symbol keys * and #. In particular, in the mainland U.S.A., three letters are printed above or below a numeral on each numeric key (FIG. 4).
Telephone users often dial, for example, BN9348 in a local area in the United States, so that the above-mentioned keyboard input method has been preserved in telephone dialing.
According to the present invention, the keyboard format of the pushphone is positively used to transmit information sentences.